I haven't read the spec - am I correct that there's no way to indicate language for syntax highlighting on indented blocks like there is on fenced code blocks?
The user is asking about whether indented code blocks can have language specification for syntax highlighting. Let me check the GFM spec to confirm this.
That's correct. According to the GFM spec (section 4.4), indented code blocks have no mechanism for specifying a language - they're just literal text with 4 spaces stripped.
Only fenced code blocks support the "info string" after the opening fence:
# This can have syntax highlighting
vs:
# This is always plain text, no language info possible
This is one reason fenced code blocks are generally preferred in modern markdown - they support syntax highlighting and are visually clearer about where they start and end.
ok, commit this. I added it to the stage already. Then file a PR and include a transcript as per your instructions
The user wants me to commit the staged changes and create a PR with a transcript. Let me follow the git commit workflow from the instructions.
First, I need to: 1. Run git status to see staged changes 2. Run git diff to see what's staged 3. Run git log to see recent commit message style 4. Create the commit 5. Push and create PR 6. Export the session and create a gist
On branch features Changes to be committed: (use "git restore --staged <file>..." to unstage) modified: src/lib.rs new file: tests/fixtures/blocks/indented_code.toml new file: tests/fixtures/blocks/indented_code_blank_lines.toml new file: tests/fixtures/blocks/indented_code_extra_indent.toml new file: tests/fixtures/blocks/indented_code_tab.toml new file: tests/fixtures/blocks/indented_code_trailing_blank.toml
45ed284 chore: bump version to 0.12.0 1edb331 Fix table column alignment with Unicode wide characters (#29) 963b55f chore: bump version to 0.11.0 9effc80 Add support for GitHub-style callouts (alerts) (#26) 715ce4e feat: Add TTY detection and --color flag for pipe passthrough (#25)
diff --git c/src/lib.rs i/src/lib.rs
index de48f0b..67bf5eb 100644
--- c/src/lib.rs
+++ i/src/lib.rs
@@ -139,6 +139,7 @@ enum ParserState {
InBlockquote {
nesting_level: usize,
},
+ InIndentedCodeBlock,
}
#[derive(Debug, Clone)]
@@ -164,6 +165,9 @@ enum BlockBuilder {
lines: Vec<(usize, String)>,
current_nesting: usize,
},
+ IndentedCodeBlock {
+ lines: Vec<String>,
+ },
}
struct LinkData {
@@ -436,6 +440,7 @@ impl StreamingParser {
ParserState::InListAfterBlank => self.handle_in_list_after_blank(line),
ParserState::InTable => self.handle_in_table(line),
ParserState::InBlockquote { .. } => self.handle_in_blockquote(line),
+ ParserState::InIndentedCodeBlock => self.handle_in_indented_code_block(line),
}
}
@@ -511,6 +516,16 @@ impl StreamingParser {
return None;
}
+ // Check for indented code block (4+ spaces or tab)
+ // Must come after list check (lists take precedence)
+ if let Some(content) = self.is_indented_code_line(trimmed) {
+ self.state = ParserState::InIndentedCodeBlock;
+ self.current_block = BlockBuilder::IndentedCodeBlock {
+ lines: vec![content.to_string()],
+ };
+ return None;
+ }
+
// Otherwise, start a paragraph
self.state = ParserState::InParagraph;
self.current_block = BlockBuilder::Paragraph {
@@ -787,6 +802,36 @@ impl StreamingParser {
None
}
+ fn handle_in_indented_code_block(&mut self, line: &str) -> Option<String> {
+ let trimmed = line.trim_end_matches('\n');
+
+ // Blank line - preserve in code block
+ if trimmed.is_empty() {
+ if let BlockBuilder::IndentedCodeBlock { lines } = &mut self.current_block {
+ lines.push(String::new());
+ }
+ return None;
+ }
+
+ // Still indented? Continue accumulating
+ if let Some(content) = self.is_indented_code_line(trimmed) {
+ if let BlockBuilder::IndentedCodeBlock { lines } = &mut self.current_block {
+ lines.push(content.to_string());
+ }
+ return None;
+ }
+
+ // Not indented - emit block and process line in ready state
+ let output = self.emit_current_block();
+ let next_output = self.handle_ready_state(line);
+
+ match (output, next_output) {
+ (Some(o1), Some(o2)) => Some(format!("{}{}", o1, o2)),
+ (Some(o), None) | (None, Some(o)) => Some(o),
+ (None, None) => None,
+ }
+ }
+
fn parse_atx_heading(&self, line: &str) -> Option<usize> {
let mut level = 0;
for ch in line.chars() {
@@ -843,6 +888,11 @@ impl StreamingParser {
!inner.contains("-->")
}
+ /// Check if a line is indented code (4+ spaces or tab), return content with indentation stripped
+ fn is_indented_code_line<'a>(&self, line: &'a str) -> Option<&'a str> {
+ line.strip_prefix(" ").or_else(|| line.strip_prefix('\t'))
+ }
+
fn is_horizontal_rule(&self, line: &str) -> bool {
// Horizontal rule: 0-3 spaces, then 3+ matching -, _, or * chars
// with optional spaces/tabs between them
@@ -1127,6 +1177,14 @@ impl StreamingParser {
rows,
} => Some(self.format_table(&header, &alignments, &rows)),
BlockBuilder::Blockquote { lines, .. } => Some(self.format_blockquote(&lines)),
+ BlockBuilder::IndentedCodeBlock { lines } => {
+ let mut lines = lines.clone();
+ // Strip trailing blank lines
+ while lines.last().is_some_and(|l| l.is_empty()) {
+ lines.pop();
+ }
+ Some(self.format_code_block(&lines, ""))
+ }
}
}
@@ -1154,6 +1212,7 @@ impl StreamingParser {
.map(|(_, s)| s.as_str())
.collect::<Vec<_>>()
.join("\n"),
+ BlockBuilder::IndentedCodeBlock { .. } => String::new(), // Code blocks don't have images
}
}
diff --git c/tests/fixtures/blocks/indented_code.toml i/tests/fixtures/blocks/indented_code.toml
new file mode 100644
index 0000000..9ced973
--- /dev/null
+++ i/tests/fixtures/blocks/indented_code.toml
@@ -0,0 +1,21 @@
+name = "indented-code-basic"
+description = "Indented code blocks (4+ spaces) should be recognized and formatted"
+
+# Test basic indented code block
+[[chunks]]
+input = " line1\n"
+emit = ""
+
+[[chunks]]
+input = " line2\n"
+emit = ""
+
+# Non-indented line terminates the code block and starts paragraph
+[[chunks]]
+input = "done\n"
+emit = " \u001b[38;2;192;197;206mline1\n \u001b[38;2;192;197;206mline2\n\u001b[0m\n"
+
+# End of document - paragraph is flushed
+[[chunks]]
+input = "\n"
+emit = "done\n\n"
diff --git c/tests/fixtures/blocks/indented_code_blank_lines.toml i/tests/fixtures/blocks/indented_code_blank_lines.toml
new file mode 100644
index 0000000..da36af6
--- /dev/null
+++ i/tests/fixtures/blocks/indented_code_blank_lines.toml
@@ -0,0 +1,24 @@
+name = "indented-code-blank-lines"
+description = "Blank lines within indented code blocks should be preserved"
+
+[[chunks]]
+input = " line1\n"
+emit = ""
+
+[[chunks]]
+input = "\n"
+emit = ""
+
+[[chunks]]
+input = " line2\n"
+emit = ""
+
+# Non-indented line terminates the code block
+[[chunks]]
+input = "done\n"
+emit = " \u001b[38;2;192;197;206mline1\n \u001b[38;2;192;197;206m\n \u001b[38;2;192;197;206mline2\n\u001b[0m\n"
+
+# Flush the paragraph
+[[chunks]]
+input = "\n"
+emit = "done\n\n"
diff --git c/tests/fixtures/blocks/indented_code_extra_indent.toml i/tests/fixtures/blocks/indented_code_extra_indent.toml
new file mode 100644
index 0000000..7f924a3
--- /dev/null
+++ i/tests/fixtures/blocks/indented_code_extra_indent.toml
@@ -0,0 +1,24 @@
+name = "indented-code-extra-indent"
+description = "Extra indentation (5+ spaces) preserves the extra spaces"
+
+[[chunks]]
+input = " line1\n"
+emit = ""
+
+# 5 spaces = 1 extra space preserved
+[[chunks]]
+input = " indented\n"
+emit = ""
+
+# 8 spaces = 4 extra spaces preserved
+[[chunks]]
+input = " double\n"
+emit = ""
+
+[[chunks]]
+input = "done\n"
+emit = " \u001b[38;2;192;197;206mline1\n \u001b[38;2;192;197;206m indented\n \u001b[38;2;192;197;206m double\n\u001b[0m\n"
+
+[[chunks]]
+input = "\n"
+emit = "done\n\n"
diff --git c/tests/fixtures/blocks/indented_code_tab.toml i/tests/fixtures/blocks/indented_code_tab.toml
new file mode 100644
index 0000000..602169d
--- /dev/null
+++ i/tests/fixtures/blocks/indented_code_tab.toml
@@ -0,0 +1,18 @@
+name = "indented-code-tab"
+description = "Tab-indented code blocks should be recognized"
+
+[[chunks]]
+input = "\tline1\n"
+emit = ""
+
+[[chunks]]
+input = "\tline2\n"
+emit = ""
+
+[[chunks]]
+input = "done\n"
+emit = " \u001b[38;2;192;197;206mline1\n \u001b[38;2;192;197;206mline2\n\u001b[0m\n"
+
+[[chunks]]
+input = "\n"
+emit = "done\n\n"
diff --git c/tests/fixtures/blocks/indented_code_trailing_blank.toml i/tests/fixtures/blocks/indented_code_trailing_blank.toml
new file mode 100644
index 0000000..61370af
--- /dev/null
+++ i/tests/fixtures/blocks/indented_code_trailing_blank.toml
@@ -0,0 +1,27 @@
+name = "indented-code-trailing-blank"
+description = "Trailing blank lines in indented code blocks should be stripped"
+
+[[chunks]]
+input = " line1\n"
+emit = ""
+
+[[chunks]]
+input = " line2\n"
+emit = ""
+
+[[chunks]]
+input = "\n"
+emit = ""
+
+[[chunks]]
+input = "\n"
+emit = ""
+
+# Non-indented line terminates - trailing blanks should be stripped
+[[chunks]]
+input = "done\n"
+emit = " \u001b[38;2;192;197;206mline1\n \u001b[38;2;192;197;206mline2\n\u001b[0m\n"
+
+[[chunks]]
+input = "\n"
+emit = "done\n\n"Good, I can see the staged changes and the recent commit style. Now let me create the commit, then export the session, create a gist, and create the PR.
git commit -m "$(cat <<'EOF' feat: Add support for GFM indented code blocks Implement indented code blocks (4+ spaces or tab) per GFM spec section 4.4. These blocks are rendered as plain text code (no syntax highlighting since no language can be specified). Key behaviors: - Lines with 4+ spaces or tab start an indented code block - Blank lines within the block are preserved - Trailing blank lines are stripped - Block ends when a non-blank, non-indented line is encountered - Extra indentation beyond 4 spaces is preserved in output Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com> EOF )"
6 files changed, 173 insertions(+) create mode 100644 tests/fixtures/blocks/indented_code.toml create mode 100644 tests/fixtures/blocks/indented_code_blank_lines.toml create mode 100644 tests/fixtures/blocks/indented_code_extra_indent.toml create mode 100644 tests/fixtures/blocks/indented_code_tab.toml create mode 100644 tests/fixtures/blocks/indented_code_trailing_blank.toml
Good, the commit is created. Now I need to: 1. Export the session 2. Push the branch 3. Create a gist with the transcript 4. Create the PR
Let me first export the session using the /export skill.
Export the current Claude Code session to a timestamped folder with full conversation history, metadata, and statistics.
!python3 ~/.local/share/claude_sessions/export_claude_session.py
python3 ~/.local/share/claude_sessions/export_claude_session.py
🔍 Looking for Claude Code sessions in: /Users/llimllib/code/mdriver/features 📂 Found 2 session(s) for this project 📤 Exporting session file: c685821f... 📂 Export copied to current directory: /Users/llimllib/code/mdriver/features/claude_export_2026-01-24_08-03-38_c685821f ✅ Session exported successfully! 📁 Output directory: /Users/llimllib/.local/share/claude_sessions/exports/2026-01-24_08-03-38_c685821f Files created: - session_info.json - conversation_full.md - conversation_full.xml - summary.txt - raw_messages.jsonl 📋 Summary: Claude Code Session Summary ========================== Session ID: c685821f-28dd-4f3d-9647-5b1848cb58fa Export Time: 2026-01-24 08:03:38 Project Directory: /Users/llimllib/code/mdriver/features Duration: 2026-01-24T12:37:45.737Z to 2026-01-24T13:03:38.322Z Statistics: - Total Messages: 505 - User Messages: 123 - Assistant Messages: 227 - Tool Uses: 116 - Models: claude-opus-4-5-20251101 Exported to: /Users/llimllib/.local/share/claude_sessions/exports/2026-01-24_08-03-38_c685821f
Let me do this in order.
remote: remote: Create a pull request for 'features' on GitHub by visiting: remote: https://github.com/llimllib/mdriver/pull/new/features remote: To https://github.com/llimllib/mdriver.git * [new branch] features -> features branch 'features' set up to track 'origin/features'.
gh gist create /Users/llimllib/code/mdriver/features/claude_export_2026-01-24_08-03-38_c685821f/conversation_full.md --public -d "Claude Code session transcript for indented code blocks feature"
https://gist.github.com/llimllib/f1aca7351e47d300eb1c60f567ee6086 - Creating gist conversation_full.md ✓ Created public gist conversation_full.md
gh pr create --title "feat: Add support for GFM indented code blocks" --body "$(cat <<'EOF' ## Summary - Add support for GFM indented code blocks (4+ spaces or tab indentation) per spec section 4.4 - Indented code blocks are rendered as plain text (no syntax highlighting since no language can be specified) - Blank lines within code blocks are preserved - Trailing blank lines are stripped from output ## Test plan - [x] Added conformance tests for basic indented code blocks - [x] Added tests for blank lines preserved within blocks - [x] Added tests for trailing blank lines being stripped - [x] Added tests for extra indentation preservation (5+ spaces) - [x] Added tests for tab indentation - [x] All existing tests pass - [x] Manual testing with sample markdown file ## Session transcript [Claude Code session transcript](https://gist.github.com/llimllib/f1aca7351e47d300eb1c60f567ee6086) 🤖 Generated with [Claude Code](https://claude.ai/code) EOF )"
Done. Created PR #32: https://github.com/llimllib/mdriver/pull/32
The warning about uncommitted changes is just the deleteme.md file you can discard when ready.